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Find the vertex , focus , latusrectum, axis and the directrix of the parabola `x^2+8x+12y+4=0`.

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To solve the problem step by step, we will start with the given equation of the parabola and then find the vertex, focus, latus rectum, axis, and directrix. ### Step 1: Rewrite the equation The given equation is: \[ x^2 + 8x + 12y + 4 = 0 \] We can rearrange this equation: \[ x^2 + 8x = -12y - 4 \] ### Step 2: Complete the square To complete the square for the left side: 1. Take the coefficient of \( x \) which is 8, halve it to get 4, and then square it to get 16. 2. Add and subtract 16 on the left side. Thus, we rewrite: \[ x^2 + 8x + 16 - 16 = -12y - 4 \] \[ (x + 4)^2 - 16 = -12y - 4 \] \[ (x + 4)^2 = -12y + 12 \] \[ (x + 4)^2 = -12(y - 1) \] ### Step 3: Identify the standard form The equation is now in the standard form of a parabola: \[ (x - h)^2 = 4p(y - k) \] where \( (h, k) \) is the vertex and \( 4p \) is the coefficient of \( (y - k) \). From our equation: - \( h = -4 \) - \( k = 1 \) - \( 4p = -12 \) which gives \( p = -3 \) ### Step 4: Find the vertex The vertex \( (h, k) \) is: \[ \text{Vertex} = (-4, 1) \] ### Step 5: Find the focus The focus is located at: \[ (h, k + p) = (-4, 1 - 3) = (-4, -2) \] ### Step 6: Find the directrix The directrix is given by the equation: \[ y = k - p = 1 + 3 = 4 \] ### Step 7: Find the latus rectum The length of the latus rectum is given by \( |4p| \): \[ |4p| = 12 \] ### Step 8: Identify the axis of the parabola The axis of the parabola is the line that passes through the vertex and is parallel to the axis of symmetry. Since this parabola opens downwards, the axis is vertical: \[ x = -4 \] ### Summary of Results - **Vertex**: \( (-4, 1) \) - **Focus**: \( (-4, -2) \) - **Directrix**: \( y = 4 \) - **Latus Rectum**: Length = 12 - **Axis**: \( x = -4 \)
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ARIHANT MATHS-PARABOLA-Exercise (Questions Asked In Previous 13 Years Exam)
  1. Find the vertex , focus , latusrectum, axis and the directrix of the ...

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  2. Tangent to the curve y=x^2+6 at a point (1,7) touches the circle x^2+y...

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  3. let P be the point (1, 0) and Q be a point on the locus y^2= 8x. The l...

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  4. The axis of parabola is along the line y=x and the distance of its ver...

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  5. The equations of the common tangents to the parabola y = x^2 and y=-...

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  6. The locus of the vertices of the family of parabolas y =[a^3x^2]/3 + [...

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  7. Angle between the tangents to the curve y=x^2-5x+6 at the points (2,0)...

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  8. Consider the circle x^2 + y^2 = 9 and the parabola y^2 = 8x. They inte...

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  9. Consider the circle x^2 + y^2 = 9 and the parabola y^2 = 8x. They inte...

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  10. Consider the circle x^2 + y^2 = 9 and the parabola y^2 = 8x. They inte...

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  11. Statement I The curve y = x^2/2+x+1 is symmetric with respect to the l...

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  12. The equation of a tangent to the parabola y^2=""8x""i s""y""=""x""+...

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  13. Consider the two curves C1 ; y^2 = 4x, C2 : x^2 + y^2 - 6x + 1 = 0 the...

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  14. A parabola has the origin as its focus and the line x=2 as the directr...

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  15. The tangent PT and the normal PN to the parabola y^2=4ax at a point P...

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  16. Let A and B be two distinct points on the parabola y^2 = 4x. If the ax...

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  17. If two tangents drawn from a point P to the parabola y2 = 4x are at ri...

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  18. Consider the parabola y^2 = 8x. Let Delta1 be the area of the triangle...

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  19. Let (x,y) be any point on the parabola y^2 = 4x. Let P be the point t...

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  20. Let (x,y) be any point on the parabola y^2 = 4x. Let P be the point t...

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  21. The shortest distance between line y-x=1 and curve x=y^2 is

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